Overview

There can be damaging physiologic effects of ingestion, inhalation, or other exposure to a broad range of chemicals, including pesticides, heavy metals, gases/vapors, drugs, and a variety of common household substances, such as bleach and ammonia. The term drug overdose (or simply overdose) describes the ingestion or application of a drug or other substance in quantities greater than are recommended, routinely prescribed, or have been researched. An overdose is generally considered harmful and dangerous as it can result in significant morbidity (permanent injury and/or disability) and mortality (death). Narcotic and stimulant use and misuse appear to be driving the increase in poisoning deaths. Alcohol and other drugs of abuse (methamphetamine, oxycodone, etc) are also important public health issues with enormous impacts on many types of injury and violence.

Statistics

While they do not give separate figures for drug overdoses and other kinds of accidental poisoning, the National Center for Health Statistics report that 19,250 people died of accidental poisoning in the U.S. in the year 2004.[1]

Types

The word "overdose" implies that there is a safe dosage; therefore, the term is commonly only applied to drugs, not poison. Drug overdoses are sometimes caused intentionally to commit suicide or as self-harm, but many drug overdoses are accidental and are usually the result of either irresponsible behavior or the misreading of product labels. Other causes of overdose include use of multiple drugs with counter indications simultaneously (for instance, heroin/certain prescription pain medications and cocaine/amphetamines/alcohol) and use after a period of abstinence or unexpected purity of the drug consumed.

A common unintentional overdose in young children involves multi-vitamins containing iron. Iron is a component of the hemoglobin molecule in blood, used to transport oxygen to living cells. When taken in small amounts, iron allows the body to replenish hemoglobin, but in large amounts it causes severe pH imbalances in the body. If this overdose is not treated with chelation therapy, it can lead to death or permanent coma.

Misconceptions

Deaths caused by adulterated drugs, most commonly heroin, are often incorrectly attributed to overdose.

Diagnosis

Diagnosis of an overdosed patient is generally straightforward if the drug is known. However, it can be very difficult if the patient cannot (or refuses to) state what drug they have overdosed on. At times, certain symptoms and signs exhibited by the patient, or blood tests, can reveal the drug in question. Even without knowing the drug, most patients can be treated with general supportive measures.

First aid

The most important point to realize in care of the overdose patient is that initial treatment is largely supportive. Making sure that the patient has a patent (unobstructed) airway and adequate circulation are key. Assuring these can buy the patient valuable time until definitive treatment can be provided either by first-responders, such as Emergency Medicine Technicians / Paramedics (EMT / EMT-P) , or by a physician in the Emergency Department. While waiting for help to arrive, valuable information can also be obtained from the above listed numbers.

In the wake of this paradigm shift to supportive care, two previously recommended initial treatments have fallen out of favor. Induced vomiting and gastric lavage ("pumping one's stomach") have been proven not only to be of little benefit, but also to be detrimental in overdose care. Syrup of ipecac was once widely used as initial treatment in overdoses by both parents and healthcare providers especially if it could be administered shortly (less than 30 min) after toxic ingestion. Though it remains available at many pharmacies, it has fallen from favor in treatment algorithms. Several factors have lead to ipecac's contraindication in nearly all overdose situations. Firstly, many toxins involved in accidental and/or intentional overdoses are CNS depressants. This results in a severely decreased level of consciousness in the victim which places them at significant risk of aspiration. Aspiration, which is the entrance of stomach contents into the lungs, not only puts the patient at risk of suffocation, but also presents a significant risk of complications such as pneumonia and/or permanent lung damage. In addition certain toxins such as hydrocarbons (gasoline), lye, and bleach cause physical damage to the oropharynx and esophagus when ingested. Regurgitation of these substances exposes these tissues to a second exposure intensifying the damage done. Lastly, any toxin that results in CNS depression can also effectively lower the seizure threshold, and with the repetitive vomiting that frequently occurs with the use ipecac can lead to seizure activity.

An informative summary of the currently accepted Ipecac guidelines can be found here. NGC

The American Academy of Clinical Toxicology (AACT) has repeatedly recommended against the use of gastric lavage. In fact, in their 2004 "Position Paper: Gastric Lavage," they said, "Gastric lavage should not be employed routinely, if ever, in the management of poisoned patients."

Depressants

First aid can prevent a death from overdose of depressants, as it may take several hours for someone to die in these cases. The common drugs in this category include opiates (ie. heroin, morphine and methadone), alcohol, and certain prescription drugs (such as Benzodiazepines). Signs of overdose are those of a depressed central nervous system — slow, infrequent or shallow breathing, blue lips or fingernails, cold or pale skin, slow or faint pulse, snoring or gurgling noises, and the inability to be aroused from nodding off (unresponsiveness).

The first step is to stay calm and try to get a response from the person by pinching the back of their arm, calling their name, or rubbing your knuckles against their chest.

If there is no response, check to make sure their airway is not blocked and see if they are breathing.

Call an ambulance. Ideally, someone should call an ambulance immediately while another person evaluates the patient and performs CPR if necessary.

Stimulants

People can overdose on stimulants, such as amphetamines, and cocaine, with symptoms such as rapid heartbeat, muscle cramps, seizures, paranoia, psychosis, confusion, loss of control of movement, vomiting, lack of consciousness, and possibly cardiac arrest. It can result in an often fatal condition known as exciteddelirium.

First aid in these cases involves staying with the person and helping them to remain calm. Move them to a quiet area, and where possible, apply a wet cloth to their neck or forehead. If unconscious, place them in the recovery position and call an ambulance.[2]

Causes of Unintentional Opiate-related Poisoning Deaths

Legitimate medical treatment with opiates

Pain is very common. About 24% of U. S. adults reported moderate to extreme pain in the past month.7 In 2005, about 19% of the 50 million United States adults who used Express Scripts, a large commercial pharmacy benefit program, received a prescription for opiates.8

Chronic opiate use is linked to the development of tolerance to its analgesic or pain relieving effect.9 Tolerance is defined as a decrease in a drug’s effect over time so that larger doses are required to achieve the same effect. Chronic opiate use also may be associated with hyperalgesia, an increase in abnormal pain sensitivity.9 In an attempt to maintain pain relief, the combination of tolerance and hyperalgesia may lead to rampant dose escalation.9

Respiratory depression, a decrease in the rate or depth of a patient’s breathing, is one of the side effects or risks of opiate use. Opiate poisoning deaths are often due to respiratory failure from respiratory depression. As with pain relief, tolerance to respiratory depression develops with chronic opiate use. However, research suggests that tolerance to respiratory depression is incomplete and may develop more slowly than tolerance to the pain relieving effect.10

Concurrent use of other central nervous system depressants like benzodiazepines and sedative-hypnotics.

The existence of other medical conditions associated with compromised respiratory function such as chronic obstructive pulmonary disease, congestive heart failure, and sleep apnea.

Misuse of Prescription Opiates

In addition to legitimately prescribed opiates, prescription opiates can be obtained in various other ways:

From a friend or relative with a prescription.

Obtained from emergency rooms through fraudulent drug-seeking means.

Purchased on the street or from the Internet.

Stolen from pharmacies.

During treatment for chronic pain, prescription opiates can be misused by taking more than the prescribed dose or by combining opiates with illicit drugs or alcohol.
Nationally, the U. S. Substance Abuse and Mental Health Services Administration’s Drug Abuse Warning Network tracks drug-related emergency department visits. These visits relate to both misuse and abuse of drugs. For prescription drugs, the definition of ‘non-medical’ use includes:

Taking more than the prescribed dose of a prescription drug.

Taking a drug prescribed for another individual.

Deliberate poisoning with a drug by another person.

Documented misuse or abuse of a prescription drug.

Opiates accounted for about one-third of all non-medical prescription drug use visits, making them the most frequently reported drugs. In 2006 in King and Snohomish counties, there were 3,529 reports of prescription opiate emergency department visits. The visits were identified as:

Drug abuse (54%).

Adverse reaction (18%).

Accidental overmedication (18%).

Childhood Poisoning

While the highest death rates occur among adults, the majority of reports are for non-fatal poison exposures to children under six years.

About 90% of the incidents occurred in a home.

52% of the incidents occurred to a child under six years.

The majority of all exposure calls (83%) were handled without transfer to a health care facility.

94% percent of exposure calls to children ages six or under were handled without transfer to a health care facility.

The most common substances involved in possible exposures are medications. For example, the top three includes analgesics, topical preparations, and cold and cough preparations. Other common exposures include personal care products, and cosmetics.

11 Substance Abuse and Mental Health Services Administration. (2006). Results from the 2005 National Survey on Drug Use and Health: National Findings. Office of Applied Studies: Rockville, MD. Retrieved February 12, 2007, from http://www.oas.samhsa.gov/p0000016.htm#2k5.